Book discharge mechanism

ABSTRACT

A book discharge mechanism for a casing-in machine features a swinging book clamping assembly with a pair of lift fingers suitable to engage a book in a back-up attitude at opposite ends of the book spine and has a pair of clamping rolls engageable with covers of the book. The book clamping assembly is angularly movable from a starting position into a discharge position; one of the rolls is automatically power operated in discharge position to effect a power assist to discharge the book with the compressive clamping engagement of the rolls additionally serving to rub-down the book covers.

United States Patent Boudreau et al.

Sept. 2, 1975 1 1 BOOK DISCHARGE MECHANISM {75] Inventors: Robert Joseph Boudreau, South Windsor; Francis J. Desantis, Waterbury, both of Conn.

[73] Assignee: The Smyth Manufacturing Company, Bloomfield, Conn.

[22] Filed: Mar. 18, 1974 [2]] Appl. No: 452,124

[52] US. Cl. .1198/243; 11/3; 214/1 Q [51] Int. Cl.,. 1. 365g 47/22 [58] Field of Search 214/1 ED, 147 R, 147 0, 214/147 T, 130 R, 10, lQA; 198/236, 237, 243, 286, 241, 242, 243, 238; 11/3, 1 R

[56] References Cited UNITED STATES PATENTS 1,835,570 12/1931 Lorenz 214/1 BD 3,160,291 12/1964 Thorp 11/3 X 3,184,079 5/1965 Buccicone 214/1 Q 3,485,387 12/1969 Sickinger et a1. 1, 214/1 Q FOREIGN PATENTS OR APPLICATIONS 53,682 11/1967 Germany .4 11/3 Primary Examiner-Frank E. Werner Altomey, Agent, or FirmPrutzman, Hayes, Kalb & Chilton [57] ABSTRACT A book discharge mechanism for a casing-in machine features a swinging book clamping assembly with a pair of lift fingers suitable to engage a book in a backup attitude at opposite ends of the book spine and has a pair of clamping rolls engageable with covers of the book. The book clamping assembly is angularly mov' able from a starting position into a discharge position; one of the rolls is automatically power operated in discharge position to effect a power assist to discharge the book with the compressive clamping engagement of the rolls additionally serving to rub-down the book covers 17 Claims, 7 Drawing Figures PATENTED 35F 21975 SHEET 1 [IF 3 PATENTEU 2 975 SHEET 2 OF 3 PATENTED 2% 3,902,593

SHEEI 3 BF 3 POWER SOURCE BOOK DISCHARGE MECHANISM This invention generally relates to book making niachines and particularly concerns a book discharge mechanism ofa general type disclosed in US. Pat. No. 3,I60,29l issued Dec. 8, I964 to James H. Thorp entitled Book Discharging Mechanism" and assigned to the assignee of this invention.

A principal object of this invention is to provide a book discharge mechanism particularly designed to handle either thin or thick books with equal ease.

Another object of this invention is to provide such a book discharge mechanism which continuously exerts positive control over each book being handled and which additionally serves to automatically rubdown opposing sides or covers of the book during its discharge for improved glue spread and elimination of air bubbles trapped between end pages and covers for significantly improved quality book manufacture.

A further object of this invention is to provide such a book discharge mechanism which not only is desirably simple in its operation but is also reliable and of relatively uncomplicated construction for quick and easy manufacture and set up with minimum service requirements.

Other objects will be in part obvious and in part pointed out more in detail hereinafter.

A better understanding of this invention will be ob tained from the following description and the accompanying drawings of an illustrative application of this invention.

In the drawings:

FIG. 1 is an isometric view, partly broken away, of the book discharge mechanism;

FIG. 2 is a view taken from an opposite side of the mechanism of FIG. I with certain parts omitted for purposes of clarity;

FIG. 3 is a view, partly broken away, schematically showing a book lifting component of the mechanism;

FIG. 4 is a view, partly broken away, showing the parts illustrated in FIG. 3 in elevation;

FIG. 5 is a side view, partly broken away, similar to FIG. 2 but schematically showing clamping rolls of the mechanism in various positions during machine cycling;

FIG. 6 is a schematic view, partly in section, of a clamping roll positioning device of the mechanism; and

FIG. 7 is a perspective view, partly broken away, of the clamping roll positioning device of FIG. 6.

The book discharge mechanism 10 of this invention is particularly suited for use with a book casing-in machine (not shown) which will be understood to have a blade 12 vertically reciprocable between a lower starting position (shown in full lines in FIG. 2) and a raised book release position (see FIG. 4) for automatically and intermittently feeding newly assembled and glued books such as at 14 for discharge from the machine. The newly completed book 14 straddles the blade I2 with opposing sides or book covers disposed on opposite sides of the blade 12 to be delivered centrally between 21 pair of parallel spaced elongate clamping rolls l6 and 18. Rolls I6 and 18 are supported for rotation on journal bearing blocks 20, 20 and 22, 22 supported for sliding movement on arms 24, 24 at opposite sides of a frame 26 ofa book clamping assembly 28. Rolls 16 and 18 are shown in broken lines in FIG. 5 in a retracted ready position for receiving the book 14 when the blade 12 is moved into raised book release position.

Blade I2 is shown longitudinally slotted (FIGS. 2 and 4) along its exposed upper edge at 30 for receiving a pair of spaced opposed, aligned knife-like book lift fingers 32, 34.

In accordance with one aspect of this invention. the book lift fingers 32, 34 are power operated by a pneumatically actuated, electrically controlled locating de vice 36 mounted on frame 26 to move fingers 32, 34 toward and away from one another between an initial Withdrawn position (shown in full lines in FIGS. 3 and 4) and a lift position (in broken lines at 38 in FIG. 4). The position of the fingers 32, 34 is controlled by the locating device 36 which features a pair of racks 40, 42 received in guideways 44, 46 formed within a mounting block 48 on frame 26 and suitably connected to the lift fingers 32, 34. Racks 40 and 42 are in meshing engagement on diametrically opposed sides of a gear 50 which will be understood to be rotatably mounted on a shaft 52 secured to the mounting block 48 on frame 26 ofthe book clamping assembly 28. In the specifically illustrated embodiment, the racks and gear mechanism for driving the lift fingers 32, 34 in unison respectively toward and away from one another is controlled by a solenoid operated valve 52 shown controlled by a cam switch 54 which is driven by and in timed relation to a machine cam shaft 56 for actuating an air cylinder 58 secured to the frame 26.

At the start of each book discharge cycle, a rod end of the cylinder 58 is exhausted through air line 60 with piston rod extended as in FIG. 3 by the application of line pressure through air line 62 applied to a piston end of the cylinder 58. Piston rod 64 is connected by a lug 66 and sliding rod 68 to lift finger 32 and rack 40 which through the gear 50 effects synchronized reciprocation of the lift fingers 32 and 34 toward and away from one another, it being seen that rod 68 is mounted on the frame 26 for longitudinal reciprocable movement. When line pressure is applied through air line 60 and air line 62 is connected to exhaust, piston rod 64 retracts and the lift fingers 32 and 34 are inserted into opposite ends of the book 14 (FIG. 4) to positively latch the book and condition it to be clamped by the opposing rolls 16, 18 compressively engaging opposite covers of the book 14.

Such book clamping action is effected by the actuation of an air cylinder 70 which is electrically controlled by a valve 72 and cam switch 73 operated by the machine cam shaft 56 (FIG. 6) in timed relation to the machine cycling. A piston rod 74 of the cylinder 70 is connected to a channel 76 (FIGS. 6 and 7) which has its opposite ends supported for movement within the elongate arms 24, 24 of the book clamping assembly frame 26. Opposite ends of the channel 76 haze fixed L shaped bearing blocks or members 20, 20 which, together with the channel ends, are provided sliding bearing support on U shaped interior faces of the arms 24, 24. The L shaped bearing members 20, 20 additionally support the shaft 78 on which clamping roll 16 is fixed for rotation. The L shaped members 20, 20 at the ends of channel 76 each have a rack 80, 80, which in the starting position of the assembly 28 (FIGS. 6 and 7), is fixed in underlying meshing engagement with a gear 82 rotatably supported on each arm 24, 24 of the frame 26 by a stud such as at 84 in FIG. 2. The ends of the other clamping roll 18 likewise are rotatably supported on bearing blocks 22, 22 mounted for sliding engagement between legs of the L shaped members 20, 20 of the channel 76 and the arms 24, 24 of the frame 26. A rack 86 is connected to each bearing block 22, 22 for overlying meshing engagement with the gears 82, 82 respectively mounted on the arms 24, 24 of the clamping assembly frame 26 in its starting position (FIGS. 6 and 7). Accordingly, opposite ends of clamping rolls ]6 and 18 are rotatably supported on the book clamping assembly frame 26 and rotation of the gears 82, 82 causes the upper racks 86, 86 to move clamping roll 18 in unison with and in a direction opposite to the movement of the opposing clamping roll 16 which is drivingly engaged at its ends to the gears 82, 82 through its lower racks 80, 80 connected to its bearing members 20, 20.

Thus, when the air cylinder 70 (FIG. 6) is pressurized through line 88 on the piston end of the cylinder 70 with its rod end exhausted through air line 90, the clamping rolls 16, 18 are simultaneously driven from their broken line retracted ready position (FIG. into a parallel operative book clamping position (shown in full lines in FIGS. 5 and 2). Blade 12 then may be permitted to descend upon actuation of a driving mechanism, not shown, suitably operated by the machine cam shaft 56, and the book 14 remains supported by the lift fingers 32, 34 and compressively engaged by the clamping rolls 16, 18.

To minimize any undesirable tendency of the rolls l6, 18 to rotate in a direction which would permit the book 14 to drop under the influence of gravity, the rolls 16, 18 are preferably mounted in overrunning clutch bearings, not shown. For completeness, it will also be understood that the above described action of the lift fingers 32, 34 and clamping rolls 16, 18 is automatically interrupted during machine cycling should no book be present on the blade 12 when it is raised into position between the clamping rolls l6 and 18. This is particularly desirable to reduce noise level, commonly associated with thin books, and to additionally extend the life of the machine components by preventing empty machine cycling. For this reason, the schematic diagrams of the controls valves 52 and 72 in FIGS. 3 and 6 each show a relay 92 and 94, respectively, which will be understood to be controlled by a suitable light source, not shown. Interruption of the light source signals the presence of a book on blade 12 to condition the solenoid valves 52 and 72 for operation in timed relation to the machine cam shaft 56 by the controlling cam switches 54 and 73.

For controlling the position of the book clamping assembly 28, a power operated positioning device 96 is provided for moving the book clamping assembly 28 and its elongate clamping rolls 16 and 18 (in their operative book clamping position) between a starting position, wherein the axes of the rolls 16, 18 are contained in a horizontal plane (such as at A in FIG. 5) and a discharge position with the axes of the rolls in an angular plane B" with the book 14 disposed in tilted rela tion to the horizontal and in alignment with a discharge outlet or belt conveyor 98 which is shown in FIGS. 1 and 5 as being in downwardly sloping relation to the horizontal.

For swinging the book clamping assembly 26, the positioning device 96 has a lever arm such as at 100 drivingly connected to pivot or swing the book clamping assembly frame 26 between its starting and discharge positions. Lever arm 100 is supported for pivotal movement on an end of a belt drive shaft 102. More specifically, a reciprocable rod 104 is drivingly connected to a pivot pin 106 fixed to the lever arm and is lowcred and raised under the control of the machine cam shaft 56 to cause a gear segment 108 on the end of lever arm 100 to mesh in driving relation to a gear 110 fixed to a drive shaft 112 secured to the book clamping assembly frame 26. Rotation of the gear 110 (counterclockwise as viewed in H6. 1) effects rotary movement of the drive shaft 112 and swings book clamping assembly 28 from its normal starting position toward discharge position. it will be understood that the machine cam shaft 56 will effect actuation of cam switch 54 to switch the supply and exhaust to air cylinder 58 to extend its piston rod 64 causing withdrawal of the lift fingers 32, 34 from the book 14 by actuating the racks 40, 42 and gear 50 as the book 14 rotates into tilted aligned relation with the discharge belt conveyor.

In accordance with still another feature of this invention, when the book clamping assembly 28 reaches discharge position, a pulley 114 fixed to shaft 78 is forced against a pair of endless belts 1 16 trained over a series of pulleys designated 1 1S driven from the main motor, not shown, of the machine. Belts 116 are driven (FIG. 1) via a drive chain 120 engaging a sprocket 122 on one end of the belt drive shaft 102 which has a gear 124 fixed to its opposite end in mesh with a pinion 126 fixed to a shaft 128 on a frame member 1'30 for supporting one of the pulleys 118 for belts 116. Upon engagement of pulley 114 of the book clamping assembly 28 with the driven moving belts 116, the shaft 78 on which the clamping roll 16 is secured is caused to immediately rotate in a direction suitable to effect a positive power drive to the book 14 in its discharge position. Thus, the book 14 compressed between the clamping rolls 16 and 18 is conveyed onto the discharge belt conveyor 98 and onto an output conveyor 132 downstream of the book discharge mechanism 10.

By virtue of the above described construction, a positive power assist is provided the book 14 which is continuously retained in control between the clamping rolls 16, 18 of the book discharge mechanism 10. If desired, an elongate book support plate 134 may be provided on the frame 26 to serve as added support during the swinging movement of the book into discharge position. An additional significant feature is provided by the disclosed construction wherein the covers of the book 14 are rubbed-down upon discharge to provide a book of improved quality. The rubbing-down action of the book clamping rolls l6 and 18 not only improves glue spread but additionally eliminates any trapped air bubbles between the end pages of the book 14 and its covers.

Upon discharge of the book 14 from the mechanism 10, the connecting rod 104 is actuated to return to a position which is raised relative to that shown in FIG. 1 to move the gear segment 108 and rotate gear 110 and drive shaft 112 to return the book clamping assembly 28 to starting position. At that point the lift fingers 32 and 34 are in their initial withdrawn position and the clamping rolls 16, 18 are opened under the control of the machine cam shaft 56 by reversing the air line connections to air cylinder 70, thereby to complete a cycle of operation with the book discharge mechanism 10 in ready condition for receiving the next newly assembled and glued book from the blade 12 of the casing-in machine.

A book discharge mechanism of the type described is particularly useful in providing a machine having increased flexibility for handling books of different shapes. Conventional book discharge mechanisms frequently require substantial clamping forces to be imposed on a book upon application of its cover in the cas? tx-end machine. This problem is particularly frequently encountered in handling thin books, for the thinner the book the greater is the need for increased clamping forces. By providing the disclosed lift fingers, the problems normally associated with book discharge is effectively minimized while at the same time insuring that there is not any need for any substantial hinge overlap in the book as required in certain conventional machine constructions. Either thin or thick books, and those without hinge overlap or overhang such as flat back and side sewn books, can readily be handled with equal ease in a machine incorporating the disclosed book discharge mechanism of this invention. Moreover, the handling of such books is achieved rapidly in a smooth yct gentle fashion.

As will be apparent to persons skilled in the art, various modifications, adaptations and variations of the foregoing specific disclosure can be made without de parting from the teachings of this invention.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as fol lows:

l. A bookmaking machine discharge mechanism for clamping and pivoting a newly assembled book into position for discharge from the machine and comprising a book clamping assembly mounted for swinging movement between a starting position for receiving a book and a discharge position angularly disposed to its starting position. the assembly including a pair of clamping rolls mounted for reciprocation in parallel relation to one another, the clamping rolls being reciprocable between an operative clamping position and a relatively retracted position for receiving a book between the rolls when the assembly is in starting position, at least one of the rolls being power operated when the assembly is in discharge position to rotate in a direction providing a positive drive for discharging the book while the clamping rolls remain in operative book clamping position.

2. The mechanism of claim 1 further including a frame for the book clamping assembly, the clamping rolls being rotatably supported on the frame and mounted thereon for reciprocation in parallel relation to one another, a pulley fixed to said one clamping roll, a power driven endless belt mounted on the mechanism and engageable with the pulley when the clamping as sembly is in discharge position to rotate said one clamping roll in a direction providing said positive drive for book discharge.

3. The mechanism of claim I wherein the clamping rolls are movable toward one another from retracted position into operative clamping position for clamping a book between the rolls when the book clamping assembly is in starting position before swinging into discharge position.

4. The mechanism of claim 1 wherein the assembly includes a pair of knife-like lift fingers mounted in Spaced opposed alignment with one another in parallel relation between the clamping rolls, the lift fingers being reciprocable toward and away from one another between an initial withdrawn position and an extended lift position, the fingers in lift position being insertable into opposite spine ends of a book received between the clamping rolls.

5. The mechanism of claim 4 wherein the fingers in lift position latch the book between the clamping rolls in their operative clamping position during swinging movement of the clamping assembly from starting position into discharge position.

6. The mechanism of claim 5 wherein the fingers move from lift position into withdrawn position when the clamping assembly reaches discharge position.

7. The mechanism of claim 4 further including a frame for the book clamping assembly, first and second racks respectively fixed to the lift fingers and supported on the frame for reciprocable movement, and a gear supported for rotation on the frame in meshing engagement with the racks for reciprocating the lift fingers in unison toward and away from one another between their withdrawn and lift positions responsive to movement of one of the racks.

8. The mechanism of claim 7 further including power operated reciprocating means drivingly connected to said one rack.

9. The mechanism of claim 8 wherein the power operated means includes an actuating cylinder and an extensible and retractable piston rod operated by the cyl inder and drivingly connected to said one rack.

10. In combination with the mechanism of claim 4, a plate reciprocable between a relatively lowered position and a relatively raised book release position for intermittently delivering newly assembled books in succession in a back-up attitude to the discharge mechanism, the plate having a longitudinally extending book supporting edge slotted to form channel means, and wherein the lift fingers are received within the channel means of the plate upon movement of the fingers into lift position when the plate is in its raised release position and the clamping assembly is in its starting position.

11. The mechanism of claim I further including a power operated positioning device drivingly connected to the book clamping assembly for swinging it between its starting and discharge positions in timed relation to receipt of a book between the clamping rolls and discharge therefrom.

12. The mechanism of claim ll wherein the axes of the clamping rolls are positioned in a generally horizontal plane when the book clamping assembly is in starting position for receiving a book between the rolls in a back-up attitude, wherein a discharge conveyor is mounted on the mechanism in downwardly sloping relation to the horizontal, and wherein the axes of the clamping rolls are positioned in generally perpendicular relation to the discharge conveyor when the book clamping assembly is in discharge position.

13. The mechanism of claim 12 wherein one of the clamping rolls has an active book engaging surface contained in a plane of the discharge conveyor surface when the clamping assembly is in discharge position.

14. The mechanism of claim 1 further including a frame, first and second bearing means mounted on the frame and respectively supporting the clamping rolls for rotation and for reciprocation in parallel relation to one another, first and second racks respectively fixed to the first and second bearing means, and a gear supported for rotation on the frame in meshing engagement with the racks for reciprocating the clamping rolls in unison toward and away from one another between their retracted and operative clamping positions responsive to movement of one of the racks 15. The mechanism of claim 14 further including power operated reciprocating means drivingly connected to said one rack.

16. The mechanism of claim l wherein the power operated means includes an actuating cylinder and an extensible and retractable piston rod operated by the cylinder and drivingly connected to said one rack.

17. A discharge mechanism for a bookmaking machine having a plate vertically reciprocal between a first position and a relatively raised release position for intermittently delivering a succession of newly assembled books in a back-up attitude to the discharge mechanism, the discharge mechanism comprising a frame having a book discharge in angular relation to the horizontal, a book clamping assembly mounted on the frame for pivotal movement between a starting position for receiving a book in a back-up attitude and a discharge position in angularly disposed relation to the starting position for discharging the book onto the book discharge, a positioning device for swinging the book clamping assembly between its starting and discharge positions. the book clamping assembly having a pair of elongate clamping rolls supported for rotation in parallel spaced relation on the frame and mounted for relative movement toward and away from one another between an operative book clamping position and a retracted ready position, and a power operated device for rotating one of the clamping rolls when the book clamping assembly is in discharge position to effeet a power assisted discharge of a book from between the rolls in their operative book clamping position. 

1. A bookmaking machine discharge mechanism for clamping and pivoting a newly assembled book into position for discharge from the machine and comprising a book clamping assembly mounted for swinging movement between a starting position for receiving a book and a discharge position angularly disposed to its starting position, the assembly including a pair of clamping rolls mounted for reciprocation in parallel relation to one another, the clamping rolls being reciprocable between an operative clamping position and a relatively retracted position for receiving a book between the rolls when the assembly is in starting position, at least one of the rolls being power operated when the assembly is in discharge position to rotate in a direction providing a positive drive for discharging the book while the clamping rolls remain in operative book clamping position.
 2. The mechanism of claim 1 further including a frame for the book clamping assembly, the clamping rolls being rotatably supported on the frame and mounted thereon for reciprocation in parallel relation to one another, a pulley fixed to said one clamping roll, a power driven endless belt mounted on the mechanism and engageable with the pulley when the clamping assembly is in discharge position to rotate said one clamping roll in a direction providing said positive drive for book discharge.
 3. The mechanism of claim 1 wherein the clamping rolls are movable toward one another from retracted position into operative clamping position for clamping a book between the rolls when the book clamping assembly is in starting position before swinging into discharge position.
 4. The mechanism of claim 1 wherein the assembly includes a pair of knife-like lift fingers mounted in spaced opposed alignment with one another in parallel relation between the clamping rolls, the lift fingers being reciprocable toward and away from one another between an initial withdrawn position and an extended lift position, the fingers in lift position being insertable into opposite spine ends of a book received between the clamping rolls.
 5. The mechanism of claim 4 wherein the fingers in lift position latch the book between the clamping rolls in their operative clamping position during swinging movement of the clamping assembly from starting position into discharge position.
 6. The mechanism of claim 5 wherein the fingers move from lift position into withdrawn position when the clamping assembly reaches discharge position.
 7. The mechanism of claim 4 further including a frame for the book clamping assembly, first and second racks respectively fixed to the lift fingers and supported on the frame for reciprocable movement, and a gear supported for rotation on the frame in meshing engagement with the racks for reciprocating the lift fingers in unison toward and away from one another between their withdrawn and lift positions responsive to movement of one of the racks.
 8. The mechanism of claim 7 further including power operated reciprocating means drivingly connected to said one rack.
 9. The mechanism of claim 8 wherein the power operated means includes an actuating cylinder and an extensible and retractable piston rod operated by the cylinder and drivingly connected to said one rack.
 10. In combination with the mechanism of claim 4, a plate reciprocable between a relatively lowered position and a relatively raised book release position for intermittently delivering newly assembled books in succession in a back-up attitude to the discharge mechanism, the plate haviNg a longitudinally extending book supporting edge slotted to form channel means, and wherein the lift fingers are received within the channel means of the plate upon movement of the fingers into lift position when the plate is in its raised release position and the clamping assembly is in its starting position.
 11. The mechanism of claim 1 further including a power operated positioning device drivingly connected to the book clamping assembly for swinging it between its starting and discharge positions in timed relation to receipt of a book between the clamping rolls and discharge therefrom.
 12. The mechanism of claim 11 wherein the axes of the clamping rolls are positioned in a generally horizontal plane when the book clamping assembly is in starting position for receiving a book between the rolls in a back-up attitude, wherein a discharge conveyor is mounted on the mechanism in downwardly sloping relation to the horizontal, and wherein the axes of the clamping rolls are positioned in generally perpendicular relation to the discharge conveyor when the book clamping assembly is in discharge position.
 13. The mechanism of claim 12 wherein one of the clamping rolls has an active book engaging surface contained in a plane of the discharge conveyor surface when the clamping assembly is in discharge position.
 14. The mechanism of claim 1 further including a frame, first and second bearing means mounted on the frame and respectively supporting the clamping rolls for rotation and for reciprocation in parallel relation to one another, first and second racks respectively fixed to the first and second bearing means, and a gear supported for rotation on the frame in meshing engagement with the racks for reciprocating the clamping rolls in unison toward and away from one another between their retracted and operative clamping positions responsive to movement of one of the racks.
 15. The mechanism of claim 14 further including power operated reciprocating means drivingly connected to said one rack.
 16. The mechanism of claim 15 wherein the power operated means includes an actuating cylinder and an extensible and retractable piston rod operated by the cylinder and drivingly connected to said one rack.
 17. A discharge mechanism for a bookmaking machine having a plate vertically reciprocal between a first position and a relatively raised release position for intermittently delivering a succession of newly assembled books in a back-up attitude to the discharge mechanism, the discharge mechanism comprising a frame having a book discharge in angular relation to the horizontal, a book clamping assembly mounted on the frame for pivotal movement between a starting position for receiving a book in a back-up attitude and a discharge position in angularly disposed relation to the starting position for discharging the book onto the book discharge, a positioning device for swinging the book clamping assembly between its starting and discharge positions, the book clamping assembly having a pair of elongate clamping rolls supported for rotation in parallel spaced relation on the frame and mounted for relative movement toward and away from one another between an operative book clamping position and a retracted ready position, and a power operated device for rotating one of the clamping rolls when the book clamping assembly is in discharge position to effect a power assisted discharge of a book from between the rolls in their operative book clamping position. 